/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it freely,
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include "DemoApplication.h"
#include "LinearMath/btIDebugDraw.h"
#include "BulletDynamics/Dynamics/btDynamicsWorld.h"

#include "BulletDynamics/ConstraintSolver/btPoint2PointConstraint.h"//picking
#include "BulletDynamics/ConstraintSolver/btGeneric6DofConstraint.h"//picking

#include "BulletCollision/CollisionShapes/btCollisionShape.h"
#include "BulletCollision/CollisionShapes/btBoxShape.h"
#include "BulletCollision/CollisionShapes/btSphereShape.h"
#include "BulletCollision/CollisionShapes/btCompoundShape.h"
#include "BulletCollision/CollisionShapes/btUniformScalingShape.h"
#include "BulletDynamics/ConstraintSolver/btConstraintSolver.h"
#include "GL_ShapeDrawer.h"
#include "LinearMath/btQuickprof.h"
#include "LinearMath/btDefaultMotionState.h"
#include "LinearMath/btSerializer.h"
#include "GLDebugFont.h"

#include "../DetectBulletVersion.h"

extern bool gDisableDeactivation;
int numObjects = 0;
const int maxNumObjects = 16384;
btTransform startTransforms[maxNumObjects];
btCollisionShape* gShapePtr[maxNumObjects];//1 rigidbody has 1 shape (no re-use of shapes)
#define SHOW_NUM_DEEP_PENETRATIONS 1

extern int gNumClampedCcdMotions;

#ifdef SHOW_NUM_DEEP_PENETRATIONS
#ifdef SIMOX_USES_OLD_BULLET
extern int gNumDeepPenetrationChecks;
#endif
extern int gNumSplitImpulseRecoveries;
#ifdef SIMOX_USES_OLD_BULLET
extern int gNumGjkChecks;
#endif
extern int gNumAlignedAllocs;
extern int gNumAlignedFree;
extern int gTotalBytesAlignedAllocs;

#endif //


DemoApplication::DemoApplication()
//see btIDebugDraw.h for modes
    :
    m_dynamicsWorld(nullptr),
    m_pickConstraint(nullptr),
    m_shootBoxShape(nullptr),
    m_cameraDistance(15.0),
    m_debugMode(0),
    m_ele(20.f),
    m_azi(0.f),
    m_cameraPosition(0.f, 0.f, 0.f),
    m_cameraTargetPosition(0.f, 0.f, 0.f),
    m_mouseOldX(0),
    m_mouseOldY(0),
    m_mouseButtons(0),
    m_modifierKeys(0),
    m_scaleBottom(0.5f),
    m_scaleFactor(2.f),
    m_cameraUp(0, 1, 0),
    m_forwardAxis(2),
    m_zoomStepSize(0.4),
    m_glutScreenWidth(0),
    m_glutScreenHeight(0),
    m_frustumZNear(1.f),
    m_frustumZFar(10000.f),
    m_ortho(0),
    m_ShootBoxInitialSpeed(40.f),
    m_stepping(true),
    m_singleStep(false),
    m_idle(false),

    m_enableshadows(false),
    m_sundirection(btVector3(1, -2, 1) * 1000),
    m_defaultContactProcessingThreshold(BT_LARGE_FLOAT)
{
#ifndef BT_NO_PROFILE
    m_profileIterator = CProfileManager::Get_Iterator();
#endif //BT_NO_PROFILE

    m_shapeDrawer = new GL_ShapeDrawer();
    m_shapeDrawer->enableTexture(true);
    m_enableshadows = false;
}



DemoApplication::~DemoApplication()
{
#ifndef BT_NO_PROFILE
    CProfileManager::Release_Iterator(m_profileIterator);
#endif //BT_NO_PROFILE

    if (m_shootBoxShape)
    {
        delete m_shootBoxShape;
    }

    if (m_shapeDrawer)
    {
        delete m_shapeDrawer;
    }
}


void DemoApplication::overrideGLShapeDrawer(GL_ShapeDrawer* shapeDrawer)
{
    shapeDrawer->enableTexture(m_shapeDrawer->hasTextureEnabled());
    delete m_shapeDrawer;
    m_shapeDrawer = shapeDrawer;
}

void DemoApplication::myinit()
{

    GLfloat light_ambient[] = { btScalar(0.2), btScalar(0.2), btScalar(0.2), btScalar(1.0) };
    GLfloat light_diffuse[] = { btScalar(1.0), btScalar(1.0), btScalar(1.0), btScalar(1.0) };
    GLfloat light_specular[] = { btScalar(1.0), btScalar(1.0), btScalar(1.0), btScalar(1.0)};
    /*  light_position is NOT default value */
    GLfloat light_position0[] = { btScalar(1.0), btScalar(10.0), btScalar(1.0), btScalar(0.0)};
    GLfloat light_position1[] = { btScalar(-1.0), btScalar(-10.0), btScalar(-1.0), btScalar(0.0) };

    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position0);

    glLightfv(GL_LIGHT1, GL_AMBIENT, light_ambient);
    glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse);
    glLightfv(GL_LIGHT1, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT1, GL_POSITION, light_position1);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_LIGHT1);


    glShadeModel(GL_SMOOTH);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);

    glClearColor(btScalar(0.7), btScalar(0.7), btScalar(0.7), btScalar(0));

    //  glEnable(GL_CULL_FACE);
    //  glCullFace(GL_BACK);
}


void    DemoApplication::setCameraDistance(float dist)
{
    m_cameraDistance  = dist;
}

float   DemoApplication::getCameraDistance()
{
    return m_cameraDistance;
}



void DemoApplication::toggleIdle()
{
    if (m_idle)
    {
        m_idle = false;
    }
    else
    {
        m_idle = true;
    }
}




void DemoApplication::updateCamera()
{


    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    btScalar rele = m_ele * btScalar(0.01745329251994329547);// rads per deg
    btScalar razi = m_azi * btScalar(0.01745329251994329547);// rads per deg


    btQuaternion rot(m_cameraUp, razi);


    btVector3 eyePos(0, 0, 0);
    eyePos[m_forwardAxis] = -m_cameraDistance;

    btVector3 forward(eyePos[0], eyePos[1], eyePos[2]);

    if (forward.length2() < SIMD_EPSILON)
    {
        forward.setValue(1.f, 0.f, 0.f);
    }

    btVector3 right = m_cameraUp.cross(forward);
    btQuaternion roll(right, -rele);

    eyePos = btMatrix3x3(rot) * btMatrix3x3(roll) * eyePos;

    m_cameraPosition[0] = eyePos.getX();
    m_cameraPosition[1] = eyePos.getY();
    m_cameraPosition[2] = eyePos.getZ();
    m_cameraPosition += m_cameraTargetPosition;

    if (m_glutScreenWidth == 0 && m_glutScreenHeight == 0)
    {
        return;
    }

    btScalar aspect;
    btVector3 extents;

    aspect = m_glutScreenWidth / (btScalar)m_glutScreenHeight;
    extents.setValue(aspect * 1.0f, 1.0f, 0);


    if (m_ortho)
    {
        // reset matrix
        glLoadIdentity();


        extents *= m_cameraDistance;
        btVector3 lower = m_cameraTargetPosition - extents;
        btVector3 upper = m_cameraTargetPosition + extents;
        //gluOrtho2D(lower.x, upper.x, lower.y, upper.y);
        glOrtho(lower.getX(), upper.getX(), lower.getY(), upper.getY(), -1000, 1000);

        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        //glTranslatef(100,210,0);
    }
    else
    {
        //      glFrustum (-aspect, aspect, -1.0, 1.0, 1.0, 10000.0);
        glFrustum(-aspect * m_frustumZNear, aspect * m_frustumZNear, -m_frustumZNear, m_frustumZNear, m_frustumZNear, m_frustumZFar);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        gluLookAt(m_cameraPosition[0], m_cameraPosition[1], m_cameraPosition[2],
                  m_cameraTargetPosition[0], m_cameraTargetPosition[1], m_cameraTargetPosition[2],
                  m_cameraUp.getX(), m_cameraUp.getY(), m_cameraUp.getZ());
    }

}



const float STEPSIZE = 5;

void DemoApplication::stepLeft()
{
    m_azi -= STEPSIZE;

    if (m_azi < 0)
    {
        m_azi += 360;
    }

    updateCamera();
}
void DemoApplication::stepRight()
{
    m_azi += STEPSIZE;

    if (m_azi >= 360)
    {
        m_azi -= 360;
    }

    updateCamera();
}
void DemoApplication::stepFront()
{
    m_ele += STEPSIZE;

    if (m_ele >= 360)
    {
        m_ele -= 360;
    }

    updateCamera();
}
void DemoApplication::stepBack()
{
    m_ele -= STEPSIZE;

    if (m_ele < 0)
    {
        m_ele += 360;
    }

    updateCamera();
}
void DemoApplication::zoomIn()
{
    m_cameraDistance -= btScalar(m_zoomStepSize);
    updateCamera();

    if (m_cameraDistance < btScalar(0.1))
    {
        m_cameraDistance = btScalar(0.1);
    }

}
void DemoApplication::zoomOut()
{
    m_cameraDistance += btScalar(m_zoomStepSize);
    updateCamera();

}










void DemoApplication::reshape(int w, int h)
{
    GLDebugResetFont(w, h);

    m_glutScreenWidth = w;
    m_glutScreenHeight = h;

    glViewport(0, 0, w, h);
    updateCamera();
}



void DemoApplication::keyboardCallback(unsigned char key, int x, int y)
{
    (void)x;
    (void)y;

    m_lastKey = 0;

#ifndef BT_NO_PROFILE

    if (key >= 0x31 && key <= 0x39)
    {
        int child = key - 0x31;
        m_profileIterator->Enter_Child(child);
    }

    if (key == 0x30)
    {
        m_profileIterator->Enter_Parent();
    }

#endif //BT_NO_PROFILE

    switch (key)
    {
        case 8:
        {
            int numObj = getDynamicsWorld()->getNumCollisionObjects();

            if (numObj)
            {
                btCollisionObject* obj = getDynamicsWorld()->getCollisionObjectArray()[numObj - 1];

                getDynamicsWorld()->removeCollisionObject(obj);
                btRigidBody* body = btRigidBody::upcast(obj);

                if (body && body->getMotionState())
                {
                    delete body->getMotionState();
                }

                delete obj;


            }

            break;
        }

        case 'q' :
#ifdef BT_USE_FREEGLUT
            //return from glutMainLoop(), detect memory leaks etc.
            glutLeaveMainLoop();
#else
            exit(0);
#endif
            break;

        case 'l' :
            stepLeft();
            break;

        case 'r' :
            stepRight();
            break;

        case 'f' :
            stepFront();
            break;

        case 'b' :
            stepBack();
            break;

        case 'z' :
            zoomIn();
            break;

        case 'x' :
            zoomOut();
            break;

        case 'i' :
            toggleIdle();
            break;

        case 'g' :
            m_enableshadows = !m_enableshadows;
            break;

        case 'u' :
            m_shapeDrawer->enableTexture(!m_shapeDrawer->enableTexture(false));
            break;

        case 'h':
            if (m_debugMode & btIDebugDraw::DBG_NoHelpText)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_NoHelpText);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_NoHelpText;
            }

            break;

        case 'w':
            if (m_debugMode & btIDebugDraw::DBG_DrawWireframe)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DrawWireframe);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DrawWireframe;
            }

            break;

        case 'p':
            if (m_debugMode & btIDebugDraw::DBG_ProfileTimings)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_ProfileTimings);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_ProfileTimings;
            }

            break;

        case '=':
        {
            int maxSerializeBufferSize = 1024 * 1024 * 5;
            btDefaultSerializer*    serializer = new btDefaultSerializer(maxSerializeBufferSize);
            //serializer->setSerializationFlags(BT_SERIALIZE_NO_DUPLICATE_ASSERT);
            m_dynamicsWorld->serialize(serializer);
            FILE* f2 = fopen("testFile.bullet", "wb");
            fwrite(serializer->getBufferPointer(), serializer->getCurrentBufferSize(), 1, f2);
            fclose(f2);
            delete serializer;
            break;

        }

        case 'm':
            if (m_debugMode & btIDebugDraw::DBG_EnableSatComparison)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_EnableSatComparison);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_EnableSatComparison;
            }

            break;

        case 'n':
            if (m_debugMode & btIDebugDraw::DBG_DisableBulletLCP)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DisableBulletLCP);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DisableBulletLCP;
            }

            break;

        case 'N':
            if (m_debugMode & btIDebugDraw::DBG_DrawNormals)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DrawNormals);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DrawNormals;
            }

            break;

        case 't' :
            if (m_debugMode & btIDebugDraw::DBG_DrawText)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DrawText);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DrawText;
            }

            break;

        case 'y':
            if (m_debugMode & btIDebugDraw::DBG_DrawFeaturesText)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DrawFeaturesText);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DrawFeaturesText;
            }

            break;

        case 'a':
            if (m_debugMode & btIDebugDraw::DBG_DrawAabb)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DrawAabb);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DrawAabb;
            }

            break;

        case 'c' :
            if (m_debugMode & btIDebugDraw::DBG_DrawContactPoints)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DrawContactPoints);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DrawContactPoints;
            }

            break;

        case 'C' :
            if (m_debugMode & btIDebugDraw::DBG_DrawConstraints)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DrawConstraints);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DrawConstraints;
            }

            break;

        case 'L' :
            if (m_debugMode & btIDebugDraw::DBG_DrawConstraintLimits)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_DrawConstraintLimits);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_DrawConstraintLimits;
            }

            break;

        case 'd' :
            if (m_debugMode & btIDebugDraw::DBG_NoDeactivation)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_NoDeactivation);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_NoDeactivation;
            }

            if (m_debugMode & btIDebugDraw::DBG_NoDeactivation)
            {
                gDisableDeactivation = true;
            }
            else
            {
                gDisableDeactivation = false;
            }

            break;




        case 'o' :
        {
            m_ortho = !m_ortho;//m_stepping = !m_stepping;
            break;
        }

        case 's' :
            clientMoveAndDisplay();
            break;

            //    case ' ' : newRandom(); break;
        case ' ':
            clientResetScene();
            break;

        case '1':
        {
            if (m_debugMode & btIDebugDraw::DBG_EnableCCD)
            {
                m_debugMode = m_debugMode & (~btIDebugDraw::DBG_EnableCCD);
            }
            else
            {
                m_debugMode |= btIDebugDraw::DBG_EnableCCD;
            }

            break;
        }

        case '.':
        {
            shootBox(getRayTo(x, y)); //getCameraTargetPosition());
            break;
        }

        case '+':
        {
            m_ShootBoxInitialSpeed += 10.f;
            break;
        }

        case '-':
        {
            m_ShootBoxInitialSpeed -= 10.f;
            break;
        }

        default:
            //        std::cout << "unused key : " << key << std::endl;
            break;
    }

    if (getDynamicsWorld() && getDynamicsWorld()->getDebugDrawer())
    {
        getDynamicsWorld()->getDebugDrawer()->setDebugMode(m_debugMode);
    }



}

void    DemoApplication::setDebugMode(int mode)
{
    m_debugMode = mode;

    if (getDynamicsWorld() && getDynamicsWorld()->getDebugDrawer())
    {
        getDynamicsWorld()->getDebugDrawer()->setDebugMode(mode);
    }
}






void DemoApplication::moveAndDisplay()
{
    if (!m_idle)
    {
        clientMoveAndDisplay();
    }
    else
    {
        displayCallback();
    }
}




void DemoApplication::displayCallback()
{
}

#define NUM_SPHERES_ON_DIAGONAL 9

void    DemoApplication::setShootBoxShape()
{
    if (!m_shootBoxShape)
    {
        btBoxShape* box = new btBoxShape(btVector3(0.5, 0.5, 0.5));
        //  box->initializePolyhedralFeatures();
        m_shootBoxShape = box;
    }
}

void    DemoApplication::shootBox(const btVector3& destination)
{

    if (m_dynamicsWorld)
    {
        float mass = 1.f;
        btTransform startTransform;
        startTransform.setIdentity();
        btVector3 camPos = getCameraPosition();
        startTransform.setOrigin(camPos);

        setShootBoxShape();

        btRigidBody* body = this->localCreateRigidBody(mass, startTransform, m_shootBoxShape);
        body->setLinearFactor(btVector3(1, 1, 1));
        //body->setRestitution(1);

        btVector3 linVel(destination[0] - camPos[0], destination[1] - camPos[1], destination[2] - camPos[2]);
        linVel.normalize();
        linVel *= m_ShootBoxInitialSpeed;

        body->getWorldTransform().setOrigin(camPos);
        body->getWorldTransform().setRotation(btQuaternion(0, 0, 0, 1));
        body->setLinearVelocity(linVel);
        body->setAngularVelocity(btVector3(0, 0, 0));
        body->setCcdMotionThreshold(0.5);
        body->setCcdSweptSphereRadius(0.4f);//value should be smaller (embedded) than the half extends of the box (see ::setShootBoxShape)
        //      printf("shootBox uid=%d\n", body->getBroadphaseHandle()->getUid());
        //      printf("camPos=%f,%f,%f\n",camPos.getX(),camPos.getY(),camPos.getZ());
        //      printf("destination=%f,%f,%f\n",destination.getX(),destination.getY(),destination.getZ());

    }
}


int gPickingConstraintId = 0;
btVector3 gOldPickingPos;
btVector3 gHitPos(-1, -1, -1);
btScalar gOldPickingDist  = 0.f;
btRigidBody* pickedBody = nullptr;//for deactivation state


btVector3   DemoApplication::getRayTo(int x, int y)
{



    if (m_ortho)
    {

        btScalar aspect;
        btVector3 extents;
        aspect = m_glutScreenWidth / (btScalar)m_glutScreenHeight;
        extents.setValue(aspect * 1.0f, 1.0f, 0);

        extents *= m_cameraDistance;
        btVector3 lower = m_cameraTargetPosition - extents;
        btVector3 upper = m_cameraTargetPosition + extents;

        btScalar u = x / btScalar(m_glutScreenWidth);
        btScalar v = (m_glutScreenHeight - y) / btScalar(m_glutScreenHeight);

        btVector3   p(0, 0, 0);
        p.setValue((1.0f - u) * lower.getX() + u * upper.getX(), (1.0f - v) * lower.getY() + v * upper.getY(), m_cameraTargetPosition.getZ());
        return p;
    }

    float top = 1.f;
    float bottom = -1.f;
    float nearPlane = 1.f;
    float tanFov = (top - bottom) * 0.5f / nearPlane;
    float fov = btScalar(2.0) * btAtan(tanFov);

    btVector3   rayFrom = getCameraPosition();
    btVector3 rayForward = (getCameraTargetPosition() - getCameraPosition());
    rayForward.normalize();
    float farPlane = 10000.f;
    rayForward *= farPlane;

    btVector3 rightOffset;
    btVector3 vertical = m_cameraUp;

    btVector3 hor;
    hor = rayForward.cross(vertical);
    hor.normalize();
    vertical = hor.cross(rayForward);
    vertical.normalize();

    float tanfov = tanf(0.5f * fov);


    hor *= 2.f * farPlane * tanfov;
    vertical *= 2.f * farPlane * tanfov;

    btScalar aspect;

    aspect = m_glutScreenWidth / (btScalar)m_glutScreenHeight;

    hor *= aspect;


    btVector3 rayToCenter = rayFrom + rayForward;
    btVector3 dHor = hor * 1.f / float(m_glutScreenWidth);
    btVector3 dVert = vertical * 1.f / float(m_glutScreenHeight);


    btVector3 rayTo = rayToCenter - 0.5f * hor + 0.5f * vertical;
    rayTo += btScalar(x) * dHor;
    rayTo -= btScalar(y) * dVert;
    return rayTo;
}

btScalar mousePickClamping = 30.f;


void DemoApplication::mouseFunc(int button, int state, int x, int y)
{
    if (state == 0)
    {
        m_mouseButtons |= 1 << button;
    }
    else
    {
        m_mouseButtons = 0;
    }

    m_mouseOldX = x;
    m_mouseOldY = y;

    updateModifierKeys();

    if ((m_modifierKeys & BT_ACTIVE_ALT) && (state == 0))
    {
        return;
    }

    //printf("button %i, state %i, x=%i,y=%i\n",button,state,x,y);
    //button 0, state 0 means left mouse down

    btVector3 rayTo = getRayTo(x, y);

    switch (button)
    {
        case 2:
        {
            if (state == 0)
            {

                shootBox(rayTo);
            }

            break;
        };

        case 1:
        {


            if (state == 0)
            {

#if 0

                //apply an impulse
                if (m_dynamicsWorld)
                {
                    btCollisionWorld::ClosestRayResultCallback rayCallback(m_cameraPosition, rayTo);
                    m_dynamicsWorld->rayTest(m_cameraPosition, rayTo, rayCallback);

                    if (rayCallback.hasHit())
                    {

                        btRigidBody* body = btRigidBody::upcast(rayCallback.m_collisionObject);

                        if (body)
                        {
                            body->setActivationState(ACTIVE_TAG);
                            btVector3 impulse = rayTo;
                            impulse.normalize();
                            float impulseStrength = 10.f;
                            impulse *= impulseStrength;
                            btVector3 relPos = rayCallback.m_hitPointWorld - body->getCenterOfMassPosition();
                            body->applyImpulse(impulse, relPos);
                        }
                    }
                }

#endif



            }
            else
            {

            }

            break;
        }

        case 0:
        {
            if (state == 0)
            {


                //add a point to point constraint for picking
                if (m_dynamicsWorld)
                {

                    btVector3 rayFrom;

                    if (m_ortho)
                    {
                        rayFrom = rayTo;
                        rayFrom.setZ(-100.f);
                    }
                    else
                    {
                        rayFrom = m_cameraPosition;
                    }

                    btCollisionWorld::ClosestRayResultCallback rayCallback(rayFrom, rayTo);
                    m_dynamicsWorld->rayTest(rayFrom, rayTo, rayCallback);

                    if (rayCallback.hasHit())
                    {

                        btVector3 pickPos = rayCallback.m_hitPointWorld;

                        pickObject(pickPos, rayCallback.m_collisionObject);

                        gOldPickingPos = rayTo;
                        gHitPos = pickPos;

                        gOldPickingDist  = (pickPos - rayFrom).length();
                    }
                }

            }
            else
            {
                removePickingConstraint();
            }

            break;

        }

        default:
        {
        }
    }

}

void DemoApplication::pickObject(const btVector3& pickPos, const btCollisionObject* hitObj)
{

    btRigidBody* body = (btRigidBody*)btRigidBody::upcast(hitObj);

    if (body)
    {
        //other exclusions?
        if (!(body->isStaticObject() || body->isKinematicObject()))
        {
            pickedBody = body;
            pickedBody->setActivationState(DISABLE_DEACTIVATION);


            //printf("pickPos=%f,%f,%f\n",pickPos.getX(),pickPos.getY(),pickPos.getZ());


            btVector3 localPivot = body->getCenterOfMassTransform().inverse() * pickPos;

            if ((m_modifierKeys & BT_ACTIVE_SHIFT) != 0)
            {
                btTransform tr;
                tr.setIdentity();
                tr.setOrigin(localPivot);
                btGeneric6DofConstraint* dof6 = new btGeneric6DofConstraint(*body, tr, false);
                dof6->setLinearLowerLimit(btVector3(0, 0, 0));
                dof6->setLinearUpperLimit(btVector3(0, 0, 0));
                dof6->setAngularLowerLimit(btVector3(0, 0, 0));
                dof6->setAngularUpperLimit(btVector3(0, 0, 0));

                m_dynamicsWorld->addConstraint(dof6, true);
                m_pickConstraint = dof6;

                dof6->setParam(BT_CONSTRAINT_STOP_CFM, 0.8, 0);
                dof6->setParam(BT_CONSTRAINT_STOP_CFM, 0.8, 1);
                dof6->setParam(BT_CONSTRAINT_STOP_CFM, 0.8, 2);
                dof6->setParam(BT_CONSTRAINT_STOP_CFM, 0.8, 3);
                dof6->setParam(BT_CONSTRAINT_STOP_CFM, 0.8, 4);
                dof6->setParam(BT_CONSTRAINT_STOP_CFM, 0.8, 5);

                dof6->setParam(BT_CONSTRAINT_STOP_ERP, 0.1, 0);
                dof6->setParam(BT_CONSTRAINT_STOP_ERP, 0.1, 1);
                dof6->setParam(BT_CONSTRAINT_STOP_ERP, 0.1, 2);
                dof6->setParam(BT_CONSTRAINT_STOP_ERP, 0.1, 3);
                dof6->setParam(BT_CONSTRAINT_STOP_ERP, 0.1, 4);
                dof6->setParam(BT_CONSTRAINT_STOP_ERP, 0.1, 5);
            }
            else
            {
                btPoint2PointConstraint* p2p = new btPoint2PointConstraint(*body, localPivot);
                m_dynamicsWorld->addConstraint(p2p, true);
                m_pickConstraint = p2p;
                p2p->m_setting.m_impulseClamp = mousePickClamping;
                //very weak constraint for picking
                p2p->m_setting.m_tau = 0.001f;
                /*
                            p2p->setParam(BT_CONSTRAINT_CFM,0.8,0);
                            p2p->setParam(BT_CONSTRAINT_CFM,0.8,1);
                            p2p->setParam(BT_CONSTRAINT_CFM,0.8,2);
                            p2p->setParam(BT_CONSTRAINT_ERP,0.1,0);
                            p2p->setParam(BT_CONSTRAINT_ERP,0.1,1);
                            p2p->setParam(BT_CONSTRAINT_ERP,0.1,2);
                            */


            }

            //save mouse position for dragging

        }
    }

}

void DemoApplication::removePickingConstraint()
{
    if (m_pickConstraint && m_dynamicsWorld)
    {
        m_dynamicsWorld->removeConstraint(m_pickConstraint);
        delete m_pickConstraint;
        //printf("removed constraint %i",gPickingConstraintId);
        m_pickConstraint = nullptr;
        pickedBody->forceActivationState(ACTIVE_TAG);
        pickedBody->setDeactivationTime(0.f);
        pickedBody = nullptr;
    }
}

void    DemoApplication::mouseMotionFunc(int x, int y)
{

    if (m_pickConstraint)
    {
        //move the constraint pivot

        if (m_pickConstraint->getConstraintType() == D6_CONSTRAINT_TYPE)
        {
            btGeneric6DofConstraint* pickCon = static_cast<btGeneric6DofConstraint*>(m_pickConstraint);

            if (pickCon)
            {
                //keep it at the same picking distance

                btVector3 newRayTo = getRayTo(x, y);
                btVector3 rayFrom;
                btVector3 oldPivotInB = pickCon->getFrameOffsetA().getOrigin();

                btVector3 newPivotB;

                if (m_ortho)
                {
                    newPivotB = oldPivotInB;
                    newPivotB.setX(newRayTo.getX());
                    newPivotB.setY(newRayTo.getY());
                }
                else
                {
                    rayFrom = m_cameraPosition;
                    btVector3 dir = newRayTo - rayFrom;
                    dir.normalize();
                    dir *= gOldPickingDist;

                    newPivotB = rayFrom + dir;
                }

                pickCon->getFrameOffsetA().setOrigin(newPivotB);
            }

        }
        else
        {
            btPoint2PointConstraint* pickCon = static_cast<btPoint2PointConstraint*>(m_pickConstraint);

            if (pickCon)
            {
                //keep it at the same picking distance

                btVector3 newRayTo = getRayTo(x, y);
                btVector3 rayFrom;
                btVector3 oldPivotInB = pickCon->getPivotInB();
                btVector3 newPivotB;

                if (m_ortho)
                {
                    newPivotB = oldPivotInB;
                    newPivotB.setX(newRayTo.getX());
                    newPivotB.setY(newRayTo.getY());
                }
                else
                {
                    rayFrom = m_cameraPosition;
                    btVector3 dir = newRayTo - rayFrom;
                    dir.normalize();
                    dir *= gOldPickingDist;

                    newPivotB = rayFrom + dir;
                }

                pickCon->setPivotB(newPivotB);
            }
        }
    }

    float dx, dy;
    dx = btScalar(x) - m_mouseOldX;
    dy = btScalar(y) - m_mouseOldY;


    ///only if ALT key is pressed (Maya style)
    if (m_modifierKeys & BT_ACTIVE_ALT)
    {
        if (m_mouseButtons & 2)
        {
            btVector3 hor = getRayTo(0, 0) - getRayTo(1, 0);
            btVector3 vert = getRayTo(0, 0) - getRayTo(0, 1);
            btScalar multiplierX = btScalar(0.001);
            btScalar multiplierY = btScalar(0.001);

            if (m_ortho)
            {
                multiplierX = 1;
                multiplierY = 1;
            }


            m_cameraTargetPosition += hor * dx * multiplierX;
            m_cameraTargetPosition += vert * dy * multiplierY;
        }

        if (m_mouseButtons & (2 << 2) && m_mouseButtons & 1)
        {
        }
        else if (m_mouseButtons & 1)
        {
            m_azi += dx * btScalar(0.2);
            m_azi = fmodf(m_azi, btScalar(360.f));
            m_ele += dy * btScalar(0.2);
            m_ele = fmodf(m_ele, btScalar(180.f));
        }
        else if (m_mouseButtons & 4)
        {
            m_cameraDistance -= dy * btScalar(0.02f);

            if (m_cameraDistance < btScalar(0.1))
            {
                m_cameraDistance = btScalar(0.1);
            }


        }
    }


    m_mouseOldX = x;
    m_mouseOldY = y;
    updateCamera();


}



btRigidBody*    DemoApplication::localCreateRigidBody(float mass, const btTransform& startTransform, btCollisionShape* shape)
{
    btAssert((!shape || shape->getShapeType() != INVALID_SHAPE_PROXYTYPE));

    //rigidbody is dynamic if and only if mass is non zero, otherwise static
    bool isDynamic = (mass != 0.f);

    btVector3 localInertia(0, 0, 0);

    if (isDynamic)
    {
        shape->calculateLocalInertia(mass, localInertia);
    }

    //using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects

#define USE_MOTIONSTATE 1
#ifdef USE_MOTIONSTATE
    btDefaultMotionState* myMotionState = new btDefaultMotionState(startTransform);

    btRigidBody::btRigidBodyConstructionInfo cInfo(mass, myMotionState, shape, localInertia);

    btRigidBody* body = new btRigidBody(cInfo);
    body->setContactProcessingThreshold(m_defaultContactProcessingThreshold);

#else
    btRigidBody* body = new btRigidBody(mass, 0, shape, localInertia);
    body->setWorldTransform(startTransform);
#endif//

    m_dynamicsWorld->addRigidBody(body);

    return body;
}

//See http://www.lighthouse3d.com/opengl/glut/index.php?bmpfontortho
void DemoApplication::setOrthographicProjection()
{

    // switch to projection mode
    glMatrixMode(GL_PROJECTION);

    // save previous matrix which contains the
    //settings for the perspective projection
    glPushMatrix();
    // reset matrix
    glLoadIdentity();
    // set a 2D orthographic projection
    gluOrtho2D(0, m_glutScreenWidth, 0, m_glutScreenHeight);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    // invert the y axis, down is positive
    glScalef(1, -1, 1);
    // mover the origin from the bottom left corner
    // to the upper left corner
    glTranslatef(btScalar(0), btScalar(-m_glutScreenHeight), btScalar(0));

}

void DemoApplication::resetPerspectiveProjection()
{

    glMatrixMode(GL_PROJECTION);
    glPopMatrix();
    glMatrixMode(GL_MODELVIEW);
    updateCamera();
}




extern CProfileIterator* m_profileIterator;

void DemoApplication::displayProfileString(int xOffset, int yStart, char* message)
{
    glRasterPos3f(btScalar(xOffset), btScalar(yStart), btScalar(0));
    GLDebugDrawString(xOffset, yStart, message);
}


void DemoApplication::showProfileInfo(int& xOffset, int& yStart, int yIncr)
{
#ifndef BT_NO_PROFILE

    static double time_since_reset = 0.f;

    if (!m_idle)
    {
        time_since_reset = CProfileManager::Get_Time_Since_Reset();
    }


    {
        //recompute profiling data, and store profile strings

        char blockTime[128];

        double totalTime = 0;

        int frames_since_reset = CProfileManager::Get_Frame_Count_Since_Reset();

        m_profileIterator->First();

        double parent_time = m_profileIterator->Is_Root() ? time_since_reset : m_profileIterator->Get_Current_Parent_Total_Time();

        {
            sprintf(blockTime, "--- Profiling: %s (total running time: %.3f ms) ---",    m_profileIterator->Get_Current_Parent_Name(), parent_time);
            displayProfileString(xOffset, yStart, blockTime);
            yStart += yIncr;
            sprintf(blockTime, "press (1,2...) to display child timings, or 0 for parent");
            displayProfileString(xOffset, yStart, blockTime);
            yStart += yIncr;

        }


        double accumulated_time = 0.f;

        for (int i = 0; !m_profileIterator->Is_Done(); m_profileIterator->Next())
        {
            double current_total_time = m_profileIterator->Get_Current_Total_Time();
            accumulated_time += current_total_time;
            double fraction = parent_time > SIMD_EPSILON ? (current_total_time / parent_time) * 100 : 0.f;

            sprintf(blockTime, "%d -- %s (%.2f %%) :: %.3f ms / frame (%d calls)",
                    ++i, m_profileIterator->Get_Current_Name(), fraction,
                    (current_total_time / (double)frames_since_reset), m_profileIterator->Get_Current_Total_Calls());
            displayProfileString(xOffset, yStart, blockTime);
            yStart += yIncr;
            totalTime += current_total_time;
        }

        sprintf(blockTime, "%s (%.3f %%) :: %.3f ms", "Unaccounted",
                // (min(0, time_since_reset - totalTime) / time_since_reset) * 100);
                parent_time > SIMD_EPSILON ? ((parent_time - accumulated_time) / parent_time) * 100 : 0.f, parent_time - accumulated_time);

        displayProfileString(xOffset, yStart, blockTime);
        yStart += yIncr;



        sprintf(blockTime, "-------------------------------------------------");
        displayProfileString(xOffset, yStart, blockTime);
        yStart += yIncr;

    }

#endif//BT_NO_PROFILE




}


//
void    DemoApplication::renderscene(int pass)
{
    btScalar    m[16];
    btMatrix3x3 rot;
    rot.setIdentity();
    const int   numObjects = m_dynamicsWorld->getNumCollisionObjects();
    btVector3 wireColor(1, 0, 0);

    for (int i = 0; i < numObjects; i++)
    {
        btCollisionObject*  colObj = m_dynamicsWorld->getCollisionObjectArray()[i];
        btRigidBody*        body = btRigidBody::upcast(colObj);

        if (body && body->getMotionState())
        {
            btDefaultMotionState* myMotionState = (btDefaultMotionState*)body->getMotionState();
            myMotionState->m_graphicsWorldTrans.getOpenGLMatrix(m);
            rot = myMotionState->m_graphicsWorldTrans.getBasis();
        }
        else
        {
            colObj->getWorldTransform().getOpenGLMatrix(m);
            rot = colObj->getWorldTransform().getBasis();
        }

        btVector3 wireColor(1.f, 1.0f, 0.5f); //wants deactivation

        if (i & 1)
        {
            wireColor = btVector3(0.f, 0.0f, 1.f);
        }

        ///color differently for active, sleeping, wantsdeactivation states
        if (colObj->getActivationState() == 1) //active
        {
            if (i & 1)
            {
                wireColor += btVector3(1.f, 0.f, 0.f);
            }
            else
            {
                wireColor += btVector3(.5f, 0.f, 0.f);
            }
        }

        if (colObj->getActivationState() == 2) //ISLAND_SLEEPING
        {
            if (i & 1)
            {
                wireColor += btVector3(0.f, 1.f, 0.f);
            }
            else
            {
                wireColor += btVector3(0.f, 0.5f, 0.f);
            }
        }

        btVector3 aabbMin(0, 0, 0), aabbMax(0, 0, 0);
        //m_dynamicsWorld->getBroadphase()->getBroadphaseAabb(aabbMin,aabbMax);

        aabbMin -= btVector3(BT_LARGE_FLOAT, BT_LARGE_FLOAT, BT_LARGE_FLOAT);
        aabbMax += btVector3(BT_LARGE_FLOAT, BT_LARGE_FLOAT, BT_LARGE_FLOAT);
        //      printf("aabbMin=(%f,%f,%f)\n",aabbMin.getX(),aabbMin.getY(),aabbMin.getZ());
        //      printf("aabbMax=(%f,%f,%f)\n",aabbMax.getX(),aabbMax.getY(),aabbMax.getZ());
        //      m_dynamicsWorld->getDebugDrawer()->drawAabb(aabbMin,aabbMax,btVector3(1,1,1));


        if (!(getDebugMode()& btIDebugDraw::DBG_DrawWireframe))
        {
            switch (pass)
            {
                case    0:
                    m_shapeDrawer->drawOpenGL(m, colObj->getCollisionShape(), wireColor, getDebugMode(), aabbMin, aabbMax);
                    break;

                case    1:
                    m_shapeDrawer->drawShadow(m, m_sundirection * rot, colObj->getCollisionShape(), aabbMin, aabbMax);
                    break;

                case    2:
                    m_shapeDrawer->drawOpenGL(m, colObj->getCollisionShape(), wireColor * btScalar(0.3), 0, aabbMin, aabbMax);
                    break;
            }
        }
    }
}

//
void DemoApplication::renderme()
{
    myinit();

    updateCamera();

    if (m_dynamicsWorld)
    {
        if (m_enableshadows)
        {
            glClear(GL_STENCIL_BUFFER_BIT);
            glEnable(GL_CULL_FACE);
            renderscene(0);

            glDisable(GL_LIGHTING);
            glDepthMask(GL_FALSE);
            glDepthFunc(GL_LEQUAL);
            glEnable(GL_STENCIL_TEST);
            glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
            glStencilFunc(GL_ALWAYS, 1, 0xFFFFFFFFL);
            glFrontFace(GL_CCW);
            glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
            renderscene(1);
            glFrontFace(GL_CW);
            glStencilOp(GL_KEEP, GL_KEEP, GL_DECR);
            renderscene(1);
            glFrontFace(GL_CCW);

            glPolygonMode(GL_FRONT, GL_FILL);
            glPolygonMode(GL_BACK, GL_FILL);
            glShadeModel(GL_SMOOTH);
            glEnable(GL_DEPTH_TEST);
            glDepthFunc(GL_LESS);
            glEnable(GL_LIGHTING);
            glDepthMask(GL_TRUE);
            glCullFace(GL_BACK);
            glFrontFace(GL_CCW);
            glEnable(GL_CULL_FACE);
            glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);

            glDepthFunc(GL_LEQUAL);
            glStencilFunc(GL_NOTEQUAL, 0, 0xFFFFFFFFL);
            glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
            glDisable(GL_LIGHTING);
            renderscene(2);
            glEnable(GL_LIGHTING);
            glDepthFunc(GL_LESS);
            glDisable(GL_STENCIL_TEST);
            glDisable(GL_CULL_FACE);
        }
        else
        {
            glDisable(GL_CULL_FACE);
            renderscene(0);
        }

        int xOffset = 10;
        int yStart = 20;
        int yIncr = 20;


        glDisable(GL_LIGHTING);
        glColor3f(0, 0, 0);

        if ((m_debugMode & btIDebugDraw::DBG_NoHelpText) == 0)
        {
            setOrthographicProjection();

            showProfileInfo(xOffset, yStart, yIncr);

#ifdef USE_QUICKPROF


            if (getDebugMode() & btIDebugDraw::DBG_ProfileTimings)
            {
                static int counter = 0;
                counter++;
                std::map<std::string, hidden::ProfileBlock*>::iterator iter;

                for (iter = btProfiler::mProfileBlocks.begin(); iter != btProfiler::mProfileBlocks.end(); ++iter)
                {
                    char blockTime[128];
                    sprintf(blockTime, "%s: %lf", &((*iter).first[0]), btProfiler::getBlockTime((*iter).first, btProfiler::BLOCK_CYCLE_SECONDS)); //BLOCK_TOTAL_PERCENT));
                    glRasterPos3f(xOffset, yStart, 0);
                    GLDebugDrawString(BMF_GetFont(BMF_kHelvetica10), blockTime);
                    yStart += yIncr;

                }

            }

#endif //USE_QUICKPROF




            resetPerspectiveProjection();
        }

        glDisable(GL_LIGHTING);


    }

    updateCamera();

}

#include "BulletCollision/BroadphaseCollision/btAxisSweep3.h"


void    DemoApplication::clientResetScene()
{
    removePickingConstraint();

#ifdef SHOW_NUM_DEEP_PENETRATIONS
#ifdef SIMOX_USES_OLD_BULLET
    gNumDeepPenetrationChecks = 0;
    gNumGjkChecks = 0;
#endif
#endif //SHOW_NUM_DEEP_PENETRATIONS

    gNumClampedCcdMotions = 0;
    int numObjects = 0;
    int i;

    if (m_dynamicsWorld)
    {
        int numConstraints = m_dynamicsWorld->getNumConstraints();

        for (i = 0; i < numConstraints; i++)
        {
            m_dynamicsWorld->getConstraint(0)->setEnabled(true);
        }

        numObjects = m_dynamicsWorld->getNumCollisionObjects();

        ///create a copy of the array, not a reference!
        btCollisionObjectArray copyArray = m_dynamicsWorld->getCollisionObjectArray();




        for (i = 0; i < numObjects; i++)
        {
            btCollisionObject* colObj = copyArray[i];
            btRigidBody* body = btRigidBody::upcast(colObj);

            if (body)
            {
                if (body->getMotionState())
                {
                    btDefaultMotionState* myMotionState = (btDefaultMotionState*)body->getMotionState();
                    myMotionState->m_graphicsWorldTrans = myMotionState->m_startWorldTrans;
                    body->setCenterOfMassTransform(myMotionState->m_graphicsWorldTrans);
                    colObj->setInterpolationWorldTransform(myMotionState->m_startWorldTrans);
                    colObj->forceActivationState(ACTIVE_TAG);
                    colObj->activate();
                    colObj->setDeactivationTime(0);
                    //colObj->setActivationState(WANTS_DEACTIVATION);
                }

                //removed cached contact points (this is not necessary if all objects have been removed from the dynamics world)
                if (m_dynamicsWorld->getBroadphase()->getOverlappingPairCache())
                {
                    m_dynamicsWorld->getBroadphase()->getOverlappingPairCache()->cleanProxyFromPairs(colObj->getBroadphaseHandle(), getDynamicsWorld()->getDispatcher());
                }

                btRigidBody* body = btRigidBody::upcast(colObj);

                if (body && !body->isStaticObject())
                {
                    btRigidBody::upcast(colObj)->setLinearVelocity(btVector3(0, 0, 0));
                    btRigidBody::upcast(colObj)->setAngularVelocity(btVector3(0, 0, 0));
                }
            }

        }

        ///reset some internal cached data in the broadphase
        m_dynamicsWorld->getBroadphase()->resetPool(getDynamicsWorld()->getDispatcher());
        m_dynamicsWorld->getConstraintSolver()->reset();

    }

}
